protocells

Encapsulating structures, or vesicles, made
of simple membrane-forming material which could have self-assembled in the
protobiological environment. The presence
of such membrane-forming material in carbonaceous
chondrites is consistent with this idea. Moreover, recent experiments
have shown that vesicular lipid bilayer structures
can grow by spontaneous addition of membrane-forming material from the surrounding
medium, and can encapsulate both ions and macromolecules.